Apparatus for the production of caustic alkali and halogen gas.



No. 674,69l. Patented May 2|, l90i. C. E. ACKER.

APPARATUS FOR THE PRODUCTION OF OAUSTIC ALKALI A'ND HALOGEN GAS.

(Application filed Apr. 24, 1900.) (No Model.) 2 Sheets-Sheet l.

WITNESSES: I INVENTOR CfldrZeJZfflO/Yez- HIS ATTORNEY m: "cums versus no, rumnu'ma, wwsHlNGroN. n. c.

no. 674,69l. Patented may 2|, 19m.

0. E. ACKEB.

APPARATUS FOR THE PRODUCTION OF CAUSTIC ALKALI AND HALOGEN GAS.

(Application filed Apr. 24, 1900.)

(No Model.) 2 Sheets-8haet 2.

%IIIII"IIIIA WITNESSES: INVENTOR M U/earieafiflaken HIS ATTORNEY m: roams rmnapcn. Pwro-uma. wmmnou. me.

UNITED STATES PATENT FFICE.

CHARLES ERNEST ACKER, OF NIAGARA FALLS, NEW YORK.

APPARATUS FOR THE PRODUCTION OF CAUSTIC ALKALl AND HALOGEN GAS.

SPECIFICATION forming part of Letters Patent N 0. 674,691, dated May 21, 1901.

Application filed April 24, 1900. Serial No; 14,101. (No model.)

To all whom it may concern:

Beit known that LCHARLES ERNEST AOKER, of Niagara Falls, county of Niagara, and State of New York, have invented a new and use ful Improvement in Apparatus for the Production of Caustic Alkali and Halogen Gas, of which the following is a specification.

The object of my invention is to economize in the production of practically anhydrous caustic akali and halogen gas.

My invention consists in an improved apparatus for the purpose.

In the accompanying drawings, Figure 1 is a longitudinal vertical section of an apparatus embodying my improvement. Fig. 2 is a transverse section of the same at the line 2 2, Fig. 1, certain parts being omitted. Fig. 3 is a transverse section of the same at the line 3 3, Fig. 1. Fig. 4 is a longitudinal vertical section illustrating a modification. Fig. 5 is a vertical section of certain parts upon an enlarged scale. Fig. 6 is a top view of the same parts upon the same scale.

Similar letters of reference designate corresponding parts in all figures.

Referring first to Figs. 1, 2, and 3, A designates an electrolytic furnace, which may be of any suitable form. As here shown, it has walls a, which may be made of basic materialas, for example, magnesia. These walls rest upon a hearth a, which may be of iron or steel. The furnace is closed by a cover a which may be of fire-clay. This cover rests upon the walls a. In the cover are openings a through which pass anodes B, preferably made of carbon, the openings 0. being,as here shown, considerably larger in diameter than the anodes. Preferably these openings Will be closed around the anodes by auxiliary covers a, preferably made of two parts in the form of half-rings. Above the cover a and in the masonry a of the furnace a recess a is formed, and in this is a body of salt 0. Below the hearth a and communicating with the interiorof the furnace A, nearone of the end walls of the latter, is a conduit D. Preferably this will be cast integral with the hearth a". It extends to the lower portion of a chamber E, and the latter may be a portion of asingle casting comprising the conduit and the hearth.

The lower portionof the chamber E communicates, by means of conduits F, with that end of the interior of the furnace A which is opposite the end whence extends the conduit D. It will be seen by reference to Fig. 3 that the conduits F are arranged one on each side.

of the conduit D.

A removable cover 6 closes the top of the chamber E, and the recess a extends down to such cover. Preferably the cover and chamber will have a double-lapped joint, made by providing the cover on its under side with an annular rib that extends into an annular groove formed in the upper end of the chamber.

A pipe H leads from the bottom of the cham ber E and is provided with any suitable device for controlling the flow of its contents from it. As here shown, a removable cap 72 is employed for this purpose. This pipe may form the negative terminal of the furnace.

G designates a steam-pipe provided with a controlling-cock g and extending into the conduit D near that end of said conduit which is in communication with the interior of the furnace A. Preferably the conduit will have a contraction d near where the steam-pipe terminates, this construction being advantageous in order to produce an action analogous to that of an injector.

In the under side of the cover 6 of the chamber E is a recess 6. From the recess 6 a pipe I, which may be made of iron or steel, extends downwardly to the outside of the furnace. As here shown, it extends directly down through the masonry. It communicates with a vessel J. From the top of the vessel J a pipe K leads to a burner, with which also communicates an air-pipe K somewhat after the man'- ner of an ordinary oxyhydrogen blowpipe; but I utilize an air-blast to create a small suction for inducing a flow of hydrogen to the burner. A cook 70 controls the burner. This burner is comprised in a small auxiliary melting-furnace L, formed in the masonry of the furnace A and communicating with the furnace A by means of a passage l, preferably inclined,so that that end which communicates with the main furnace A will always be submerged in the contents of the latter. The

' the conduit D to the chamber E.

molten salt in this auxiliary furnace will norbe consumed in the auxiliary melting-furnace mally be at the same level as the contents of I L, where the salt is melted for maintaining the main furnace A. Whenever the level rises in the auxiliary furnace, there will be a flow into the main furnace A. Owing to the fact that the level in the two furnaces will be normally the same it is possible to ascertain the level in the main furnace by looking through the hole provided for the passage of the burner K into the auxiliary furnace, that hole being of sufficient size for the purpose. A pipe S, extending from the top of the auxiliary furnace, provides for carrying away gaseous products of combustion.

Salt to be treated in the furnace, if supplied through a hopper or chamber M and fed by a worm N into a pipe 0, leading into the melting-furnace L, may be supplied to the electrolytic furnace in molten condition at a uniform rate. A pulleyn upon the shaft of the worm N derives motion from a belt it, set in motion by a suitable motor. A plug T, fitting a hole in the cover a and provided with a handle extending above the body of salt 0, may be manipulated for the purpose of permitting some of the body of salt O to flow into the main furnace A. Thus an independent feed will be possible. From the upper part of the interior of the furnace A a channel P extends through the masonry and communicates with a pipe 19. It is intended that the body of salt 0 shall be maintained constantly in sufficient quantity in the recess a to form a seal for the openings to the covers a and a. Lead in a molten state may be introduced through one of the anode-openin gs a in quantity sufficient to fill the conduit D and cover the hearth a, an anode and its auxiliary cover of being for this purpose temporarily removed. Immediately afterward the salte. g. sodium chlorid-may be introduced in a molten state in the same manner as the lead. Then the anode,with its auxiliary cover,will be replaced and the full current turned on. After the operation shall have been fully started salt is supplied by means of the hopper M, worm N, pipe 0, and auxiliary furnace L, entering the main furnace A in a molten state. An alloy of sodium and lead will be formed. Steam under pressure escaping fromthe pipe G will produce a rapid circulation through It will be decomposed in transit within the conduit by the sodium in the alloy, and caustic soda and hydrogen will result. Through the conduit D flow to the chamber E caustic soda, im poverished alloy, and hydrogen. In the chamber E a separation occurs. Impoverished alloy or lead will return from the chamber E by the conduits F to the interior of the main furnace A, Where it will again act as a cathode and take up sodium. From the chamber E the hydrogen will escape through the pipe I into the vessel J. ten caustic soda. From the vessel J the hydrogen will pass through the pipe K and will would otherwise be the case.

Thence will also fiow molthe supply of salt in the main furnace A.

As already indicated, the contents of the furnace may at any time be removed through the pipe H.

Ohlorin gas will escape through the conduit P and pipe 19.

The contents of the furnace A are to be maintained molten and fluid. The temperature necessary to secure this condition will preferably be maintained by employing a suitable electric-current density on the anodes and cathode, with ahigher electromotive force than would ordinarily be required to decompose the molten salt. In other words, if reliance is placed upon the current to make up the loss of heat due to radiation and conduction the electrical energy will have to be in excess of that needed for the decomposition of the molten salt only. The heat resulting from the combination of the sodium with the oxygen of the steam will compensate to a considerable extent for loss of temperature incident to radiation and conduction. This is possible because of causing the oxidation of sodium in close proximity to the molten electrolyte or causing the impoverished alloy or lead at the somewhat higher temperature resulting from the reaction to immediately return and come in contact With or proximity to the molten electrolyte, so as to impart some of its heat thereto, thus reducing the amount of electrical energy required to be converted into heat energy to maintain the electrolyte in the molten state and making possible the operation of the furnace at a lower voltage and at a higher efficiency than Burning the resultant hydrogen in the auxiliary furnace will obviously to some extent still further reduce the heat energy, which otherwise would have to be supplied from an external source or from a higher electromotive force or current. There may of course be some other and additional external source of heat. Thus an auxiliary supply of fuel-gas may be drawn through a pipe V and be consumed in the small melting-furnace together with or independently of the hydrogen.

Caustic alkali formed at the high temperature contemplated will be practically anhydrous.

It will be seen that there is a circulation continuously in the same direction through an endless circuit, that such circuit comprises two branches, one of said branches being the hearth of the main furnace A, containing that part of the molten metal in contact. with the electrolyte, and the other the conduit D and its connections, that steam is introduced into the circulation, that alkali metal will be oxidized by the steam during transit, and that in such circuit or circulation one or more anodes are arranged. It is more advantageous to cause the necessary circulation by steam than by mechanical devices, for the latter involve moving parts requiring attention, and this advantage is independent of the advantage due to the utilization of the heat of combination during circulation.

Turning now to Figs. 4, 5, and 6, A designates a furnace like the one already described. It may have a cover and appurtenances of like construction similarlysealed. At its bottom is a hearth C6 and beneath it a conduit D, communicating with the interior of the furnace near one end, as in the example of myinvention already described. In this modification (illustrated by Figs. 4, 5, and 6) the conduitD terminates in a well D at that end which is farthest away from its communication with the furnace A. It will be observed that the bottom of the conduit D is inclined toward the well, or, in other words, it is arranged at an angle. It will also be noticed that the well is at a lower level. A pipe H, like that already described, communicates with the bottom of the well and may form the negative terminal. Above the well is a chamber E, communicating by conduits F with the interior of the furnace at the opposite end from that where the furnace is in communication with the conduit D. Through a partition forming the bottom of the chamber and the top of the well D vertically extends a conduit Q, which is open at both ends. This partition is shown as made of a removable piece and may be made of iron or steel. A steam-pipe G, havinga controlling-cock g and preferably made of iron or steel, extends downwardly through the cover of the chamber E and thence through the conduit Q, nearly to the bottom of the latter. This conduit Q may be made of iron or steel. At the lower end of the steam-pipe is a distributer R, which, as here shown, consists of a cap secured by means of a screw-thread to the lower end of the steam-pipe, so that there will be a space between its bottom and the lower end of the steam-pipe. In this cap are a number of passages *r, which communicate with its interior below the steam-pipe and extend through the upper end of the cap. Steam passing down through the steam-pipe will escape through the passages r in an upward direction. In this modification the circulation takes place from the furnace A into the upper end of the conduit D, thence down into the Well D, thence through the conduit Q into the chamber E, and thence into the furnace A. Steam will escape in an upward direction into the conduit Q and will thereby elevate the alloy and oxidize the sodium in transit. Hydrogen and caustic soda pass through a pipe I, which communicates with pipes l I. The caustic soda flows through the pipe I into a drum U, and the hydrogen passes off into an auxiliary melting-furnace similar to that shown in Fig. 1 or any suitable receiver, or it may be permitted to escape into the air. This modification has ad- In both examples of my invention it will be understood that the decomposition of the steam and the formation of caustic soda and hydrogen will occur in transit.

I do not wish to be confined to producing caustic soda and chlorin by my invention, as I may employ the invention for the production of some other caustic alkali and gas.

What I claim as new, and desire to secure by Letters Patent, is

1. In an apparatus for the manufacture of molten caustic alkali, the combination of a furnace for containing a molten electrolyte, an anode, afusible metallic cathode,electrical connections for such electrodes, a conduit communicating with said furnace, and means comprising a discharging device beneath the surface of the fusible cathode for emitting steam under pressure in such direction as to effect circulation through the furnace and conduit, substantially as specified.

2. In an apparatus for the manufacture of molten caustic alkali, the combination of a furnace for containing a molten electrolyte, an anode,a fusible metallic cathode,electrical connections for such electrodes, a conduit communicating with said furnace, a chamber communicating with the conduit, and means comprising a discharging device beneath the surface of the fusible cathode for emitting steam under pressure in such direction as to effect circulation through the furnace, conduit and chamber, substantially as specified.

3. In an apparatus for the manufacture of molten caustic alkali, the combination of a furnace for containing a molten electrolyte, an anode,a fusible metallic cathode,electrical connections for such electrodes, a conduit communicating with said furnace, a chamber communicating with the conduit, another conduit communicating with the chamber and the furnace, and means comprising a discharging device beneath the surface of the fusible cathode for emitting steam under pressure in such direction as to effect circulation through said parts, substantially as specified.

4. In an apparatus for the manufacture of molten caustic alkali, the combination of a furnace for containing a molten electrolyte, an anode, a fusible metallic cathode,electrical connections for such electrodes, a conduit communicating with said furnace, a chamber communicating with the conduit, a pipe extending downwardly from said chamber, and means comprising a discharging device beneath the surface of the fusible cathode for emitting steam under pressure in such direction as to effect circulation, substantially as specified.

5. In an apparatus for the manufacture of molten caustic alkali, the combination of a main electrolytic furnace for containing a molten electrolyte, an anode, a fusible metallic cathode, electrical connections for such electrodes, an auxiliary furnace, a conduit or chamber in fluid communication with'the main electrolytic furnace, means comprising a discharging device beneath the surface of the fusible cathode for emitting steam under pressure into the fluid metallic contents of said conduit, or chamber, in proper direction to cause circulation, and means for receiving hydrogen obtained from the decomposition of the steam and for conducting it to the anxiliary furnace for combustion.

6. In an apparatus for the manufacture of molten caustic alkali, the combination of a furnace for containing a molten electrolyte, an anode, afusible metallic cathode, electrical connections for such electrodes, an upright conduit communicating with said furnace, a chamber communicating with the conduit, and means comprising a discharging device beneath the surface of the fusible cathode for emitting steam under pressure, so as to efiect circulation through the furnace, conduit and chamber.

7. In an apparatus for the manufacture of molten caustic alkali, the combination of a furnace for containing a molten electrolyte, an anode, afusible metallic cathode, electrical connections for such electrodes, an upright conduit communicating with said furnace, a chamber communicating with the conduit, and a pipe extending downwardly into said conduit and having in its lower portion means, comprising a discharging device beneath the surface of the fusible cathode for emitting steam under pressure so as to effect circulation through the furnace, conduit and chamber.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES ERNEST ACKER.

\Vitnesses:

Gno. E. ORUsE,

J. M. RIEMANN. 

